Device for breaking a launching rack-to-missile umbilical cord

ABSTRACT

In a missile launching apparatus in which a missile is coupled to a launching rack by an umbilical cord which passes through an opening in the skin or fairing of the missile, there is provided a device for severing the umbilical cord. This device includes a rotatable disk provided wth a hole which is offset relative to the axis of rotation of the disk and through which hole the cord passes. A cable is provided connecting the disk with the launching rack so that upon launching, the disk is rotated through a fraction of a turn. The disk is provided with a knife edge bordering part of the aforementioned hole for purposes of severing the umbilical cord. The hole in the disk is provided in a half of the disk and the other half of the disk is at least substantially imperforate. This latter half of the disk operates to obturate the opening in the skin of the missile after the umbilical cord has been severed. A safety pin is provided to lock the disk against rotation prior to launching of the missile and this pin is of a strength to be sheared when the disk is rotated by the aforesaid cable. In addition, there may be provided a switch which includes an actuator bearing against the disk and adapted to enter the aforesaid hole upon rotation of the disk in order to actuate the switch.

tates atttt Taharie et a1.

[ DEVICE FOR BREAKING A LAUNCHHNG RACK-TO-MKSSHLE UMBIILIICAL CORD [75] Inventors: Frederic Louis Joseph Taharie,

Saint-Tropez; Albert Bernard, Cannes; Georges Gilbert Saint-Auhin, Gassin, all of France [73] Assignee: Etat Francais represente par le Ministre Charge de la Defense Nationale Delegation, Ministerielle pour IArmement, Paris, France [22] Filed: Mar. 30, 1972 [21] Appl. No.: 239,654

[30] Foreign Application Priority Data Apr. 2, 1971 France 71.11641 [52] U.S. C1 89/1311, 83/199, 89/l.8 [51] Int. Cl F41t 3/04 [58] Field of Search 89/l.811; 114/20; 244/3.1l, 3.12; 83/199 [56] References Cited UNITED STATES PATENTS 2,870,676 1/1959 Radowski et al. 89/l.811 3,167,047 l/1965 Eng ..89/l.81lX

Primary ExaminerSamuel W. Engle Attorney-Eric H. Waters, et al.

LAUNCH/N6 R'ACK ABSTRACT In a missile launching apparatus in which a missile is coupled to a launching rack by an umbilical cord which passes through an opening in the skin or fairing of the missile, there is provided a device for severing the umbilical cord. This device includes a rotatable disk provided wth a hole which is offset relative to the axis of rotation of the disk and through which hole the cord passes. A cable is provided connecting the disk with the launching rack so that upon launching, the disk is rotated through a fraction of a turn. The disk is provided with a knife edge bordering part of the aforementioned hole for purposes of severing the umbilical cord. The hole in the disk is provided in a half of the disk and the other half of the disk is at least substantially imperforate. This latter half of the disk operates to obturate the opening in the skin of the missile after the umbilical cord has been severed. A safety pin is provided to lock the disk against rotation prior to launching of the missile and this pin is of a strength to be sheared when the disk is rotated by the aforesaid cable. In addition, there may be provided a switch which includes an actuator bearing against the disk and adapted to enter the aforesaid hole upon rotation of the disk in order to actuate the switch.

sum 1 or 2 PATENTED UEBZSIQYS LAUNCH/N6 RACK DEVICE FOR BREAKING A LAUNCI'IING RACK-TO-MISSILE UMBILICAL CORD FIELD OF THE INVENTION This invention relates to breaking devices for cutting launching rack-to-missile umbilical cords after the launching of missiles.

BACKGROUND OF THE INVENTION It is known that missiles such as torpedoes or rockets are connected with associated launching racks by means of multiwire cables through which data is transmitted to the missile up to the last moment prior to launching. This connection is broken only after the take-off of the missle.

Breakwire devices operated by pulling force are commonly used. In such case, the cable includes a length of smaller cross-section which breaks under the pulling force which results upon launching.

The pulling force method leads to heavy stresses when a large number of wires are involved. Moreover, it is difficult to evaluate this pulling force precisely as a result of which the missile can be caused to deviate from the calculated trajectory.

Breaking devices using jettisonable connectors are also well known. However, this technique can lead to functional failures due to poor contacts, and hence there is a lack of reliability. Furthermore, the design of a jettisonable connector raises problems when disconnection is to take place in a high pressure area.

ln any event, the two above-mentioned cases are, for the missile, detrimental as regards performance. They increase missile drag and preclude silent operation when required. Also, they complicate the design of missile fairings, especially when the latter must support external pressures.

SUMMARY OF THE INVENTION According to the invention, a device is provided which disposes of the aforesaid disadvantages while allowing not only the breaking of the umbilical cord but also the blanking off of the cord passage through the missile fairing. The invention moreover eliminates any problem due to electrical circuit continuity as no connectors are used which must be plugged into sockets. The invention also avoids the need for weakened wire sections to enable breaking in response to a pulling force. Thus, the reliability of missiles equipped in accordance with this invention is greatly improved.

It will be specifically seen that an object of the invention is to provide a device allowing a cable to be separated flush with the skin of the associated missle.

With a view toward clarifying a discussion of the invention, there will be considered the case of a connecting cord containing electrical wires, which is the most commonly used from. This case is not exhaustive because the device of this invention can also be used for breaking or blanking off any flexible connection between a missile and its launching rack (flexible conduit, for instance). Such a cable or flexible conduit will be referred herein to as the umbilical cord.

Within the scope of this invention, a device for cutting, at the take-off of a missile, the launching rack-tomissile umbilical cord consists, for example, of a rotary disk provided with a hole offset in relation to the rotation axis, The umbilical cord conduit is routed through this hole. One end of a tensioning cable is wound about fore, when the disk has rotated by half a turn, during which it cuts the umbilical cord, the disk covers the cut end of the umbilical cord and blanks off the passage hole. As the disk is located close to the missile fairing and nearly parallel with its surface, the fairing surface continuity is almost restored after the passage has been blanked off. Before missile take-off, the disk is blocked by a safety pin which is sheared by the disk rotation. BRIEF DESCRIPTION OF DRAWING Th various characteristics and results of the invention will be better understood from the following description of a preferred embodiment given as an example and shown in the attached drawings in which:

FIG. I is a lengthwise cross-sectional view of a device provided in accordance with the invention, prior to missile take-off;

FIG. 2 is a cross-sectional view taken along line lI-Il of FIG. I;

FIG. 3 is a cross-sectional view taken along line III- III of FIG. I; and

FIG. 4 corresponds to FIG. I, but shows the structure after missile take-off.

DETAILED DESCRIPTION in FIGS. 1 and 2, element I is a multiwire umbilical cord connecting a missile 2 to a launching rack LR. Missile 2 may be, for example, a torpedo, a surface-tosurface or surface-to-ground missile to be launched from a submarine or some other type of missile.

Part 4 is a detachable section of the missile fairing or skin which serves as a cover for the device.

Element 5 is a mount for the device and it is traversed by cable ll through a packing gland 6 sealed by a packing 7.

The device includes a disk 8 which is allowed to rotate about a rounded bearing surface 8a of mount 5. Disk 8 includes a portion provided with a hole 9 through which cable I is routed. The disk is generally parallel to the missile skin and preferably rotates about an axis perpendicular to the longitudinal axis of the missile.

The edge of hole 9 is bevelled to form a knife edge 10 along a given length of the rim. A tensioning cable 11 has one end lllla would around the rim of disk 8 while the other cable end llllb is attached to the launching rack LR.

Cable 11 includes two strands forming a loop 13 (FIG. 4) which engages with a stud 12 (FIG. 2) protruding from the rim of disk 8. The cable is wound on about one-half of the disk rim. Hole 9 is located in the other half of disk 8. At the time of missile take-off, disk 8 rotates through half of a turn under the control of cable 11 and edge It) cuts cable ll.

Once the disk has rotated, the disk half or portion with no hole (i.e., an imperforate portion) is situated on the left-hand side of FIG. 2. The disk then covers the cut end of cable I and blanks off the cable passage opening in cover 4.

Prior to missile take-off, the disk is prevented from rotating by safety pin 14. This very weak pin is sheared by the rotating disk upon start of missile movement. The force required to shear pin 14 and to cut cable 1 is about 500 Newtons.

To improve tightness around the cut end of cable 1 without mechanical action on the cable, the device is provided with a bushing loaded by spring 16. This bushing is released upon rotation of disk 8 and applies packing 17 against the lower surface of disk 8. Thereby, the cut end of the cable is insulated from the exterior by means of the disk 8 which forms a cover. The bushing 15, spring 16 and packing l7 assure the tightness of the cover. FIG. 4 shows the end lb of the cable insulated from the exterior.

The device also includes an automatic contactor 18 which automatically closes contact 19 after missile take-off. Push rod is pushed against the lower surface of disk 8 by spring 21. Once the disk has rotated, push rod 20 enters into hole 9 of disk 8 and closes contact 19. The latter can automatically control any operation the starting of which must precisely coincide with missile take-off (starting of a time relay for instance).

FIG. 4 illustrates the section la of cable 1 remaining attached to the launching rack and cable end 1b which, after the cutting action, is covered by disk 8. Bushing 15 is pushed back by spring 16 and applies packing 17 against the lower surface of disk 8. Also shown is termination loop 13 of tensioning cable 11 freed from protruding stud 12 after disk 8 has rotated through half of a turn. This release takes place without exerting any pulling force whatsoever on the missile. FIG. 4 also shows the automatic contactor 18 in the position it occupies when push rod 20 is engaged in hole 9 and contact w is closed.

Without departing from the scope of this invention, various modifications involving equivalent functions can be employed in the device, the above description being given solely as an example.

What is claimed is:

1. In a missile launching apparatus in which a missile is coupled to a launching rack by an umbilical cord which passes through an opening in the skin of the missile, a device comprising a rotatable disk having an axis of rotation and provided with a hole offset relative to said axis and through which said cord passes, at least part of said hole being bordered by a knife edge, and a cable distinct from said cord and peripherally engaging a portion of said disk approximately equal to half a circle, said hole being situated out of said portion, the peripheral engagement of the cable with the disk enabling said cable to rotate said disk by half a turn responsive to movement of the missile relative to said rack, said cable being coupled between said disk and said rack.

2. A device as claimed in claim 1 comprising a switch including an actuator bearing against said disk for entering said hole upon rotation of said disk to actuate the switch.

3. A device as claimed in claim 1 comprising a displaceable bushing actuated by rotation of said disk, a spring loading said bushing, and a packing applied by the bushing around said cord when the latter is severed.

4. A device as claimed in claim 1 comprising a lug on said disk detachably engaged by said cable. 

1. In a missile launching apparatus in which a missile is coupled to a launching rack by an umbilical cord which passes through an opening in the skin of the missile, a device comprising a rotatable disk having an axis of rotation and provided with a hole offset relative to said axis and through which said cord passes, at least part of said hole being bordered by a knife edge, and a cable distinct from said cord and peripherally engaging a portion of said disk approximately equal to half a circle, said hole being situated out of said portion, the peripheral engagement of the cable with the disk enabling said cable to rotate said disk by half a turn responsive to movement of the missile relative to said rack, said cable being coupled between said disk and said rack.
 2. A device as claimed in claim 1 comprising a switch including an actuator bearing against said disk for entering said hole upon rotation of said disk to actuate the switch.
 3. A device as claimed in claim 1 comprising a displaceable bushing actuated by rotation of said disk, a spring loading said bushing, and a packing applied by the bushing around said cord when the latter is severed.
 4. A device as claimed in claim 1 comprising a lug on said disk detachably engaged by said cable. 